Observation: in the presence of hooks that can mutate the local filesystem,
there is a general problem that the "order of operation" for commit processing
needs to be explicitly defined. There was another bug (can't find it at the
moment) wherein a file being committed was modified by a commit script.

The main point is that anything of the form "read after write after read" is bad
news, and the only way to resolve these in general is to have a well defined and
documented processing model for handling the workspace.